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Over the past decades, a multitude of experimental drugs have been shown to delay disease progression in preclinical animal models of amyotrophic lateral sclerosis (ALS) but failed to show efficacy in human clinical trials or are still waiting for approval under Phase I-III trials. Riluzole, a glutamatergic neurotransmission inhibitor, is the only drug approved by the USA Food and Drug Administration for ALS treatment with modest benefits on survival. Recently, an antioxidant drug, edaravone, developed by Mitsubishi Tanabe Pharma was found to be effective in halting ALS progression during early stages. The newly approved drug edaravone is a force multiplier for ALS treatment. This short report provides an overview of the two drugs that have been approved for ALS treatment and highlights an update on the timeline of drug development, how clinical trials were done, the outcome of these trials, primary endpoint, mechanism of actions, dosing information, administration, side effects, and storage procedures. Moreover, we also discussed the pressing issues and challenges of ALS clinical trials and drug developments as well as future outlook., (© 2018 Wiley Periodicals, Inc.)

Background: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the selective loss of motor neurons (MN) in the brain stem and spinal cord. Intracellular disruptions of cytosolic and mitochondrial calcium have been associated with selective MN degeneration, but the underlying mechanisms are not well understood. The present evidence supports a hypothesis that mitochondria are a target of mutant SOD1-mediated toxicity in familial amyotrophic lateral sclerosis (fALS) and intracellular alterations of cytosolic and mitochondrial calcium might aggravate the course of this neurodegenerative disease. In this study, we used a fluorescence charged cool device (CCD) imaging system to separate and simultaneously monitor cytosolic and mitochondrial calcium concentrations in individual cells in an established cellular model of ALS., Results: To gain insights into the molecular mechanisms of SOD1(G93A) associated motor neuron disease, we simultaneously monitored cytosolic and mitochondrial calcium concentrations in individual cells. Voltage - dependent cytosolic Ca2+ elevations and mitochondria - controlled calcium release mechanisms were monitored after loading cells with fluorescent dyes fura-2 and rhod-2. Interestingly, comparable voltage-dependent cytosolic Ca2+ elevations in WT (SH-SY5Y(WT)) and G93A (SH-SY5Y(G93A)) expressing cells were observed. In contrast, mitochondrial intracellular Ca2+ release responses evoked by bath application of the mitochondrial toxin FCCP were significantly smaller in G93A expressing cells, suggesting impaired calcium stores. Pharmacological experiments further supported the concept that the presence of G93A severely disrupts mitochondrial Ca2+ regulation., Conclusion: In this study, by fluorescence measurement of cytosolic calcium and using simultaneous [Ca2+]i and [Ca2+]mito measurements, we are able to separate and simultaneously monitor cytosolic and mitochondrial calcium concentrations in individual cells an established cellular model of ALS. The primary goals of this paper are (1) method development, and (2) screening for deficits in mutant cells on the single cell level. On the technological level, our method promises to serve as a valuable tool to identify mitochondrial and Ca2+-related defects during G93A-mediated MN degeneration. In addition, our experiments support a model where a specialized interplay between cytosolic calcium profiles and mitochondrial mechanisms contribute to the selective degeneration of neurons in ALS.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the selective loss of defined motoneuron populations in the brainstem and spinal cord. Although low cytosolic calcium ([Ca(2+)](i)) buffering and a strong interaction between metabolic mechanisms and [Ca(2+)](i) have been associated with selective motoneuron vulnerability, the underlying cellular mechanisms are barely understood. To elucidate the underlying molecular events, we used rapid charge-cooled device imaging to evaluate Ca(2+) signaling and metabolic signatures in the brainstem slices of SOD1(G93A) mice, the mouse model of human ALS, at 8 to 9 and 14 to 15 weeks of age, corresponding to the presymptomatic and symptomatic stages of motor dysfunction, respectively, and compared the results with corresponding age-matched wild-type littermates. We also monitored the mitochondrial membrane potential (Delta(Psim)) of brainstem motoneurons, a valuable tool for characterizing the metabolic signature of intrinsic energy profiles and considered to be a good experimental measure for monitoring energy metabolism in cells. We found that different pharmacological interventions substantially disrupt Delta(Psim) in SOD1(G93A) motoneurons during the symptomatic stage. Furthermore, we investigated the impact of impaired mitochondrial mechanisms on [Ca(2+)](i) regulation by using the membrane-permeable indicator fura-acetoxy methyl ester. Taken together, the results indicate that mitochondrial disruptions are critical elements of SOD1(G93A)-mediated motoneuron degeneration in which selective motoneuron vulnerability results from a synergistic accumulation of risk factors, including the disruption of electrochemical potential, low Ca(2+) buffering, and strong mitochondrial control of [Ca(2+)](i). The stabilization of mitochondria-related signal cascades may represent a useful strategy for clinical neuroprotection in ALS.

Background: Infections can aggravate the course of neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Mutations in the anti-oxidant enzyme Cu,Zn superoxide dismutase (EC 1.15.1.1, SOD1) are associated with familial ALS. Streptococcus pneumoniae, the most frequent respiratory pathogen, causes damage by the action of the cholesterol-binding virulence factor pneumolysin and by stimulation of the innate immune system, particularly via Toll-like-receptor 2. Methods: SH-SY5Y neuroblastoma cells transfected with the G93A mutant of SOD1 typical for familial ALS (G93A-SOD1) and SH-SY5Y neuroblastoma cells transfected with wildtype SOD1 were both exposed to pneumolysin and in co-cultures with cultured human macrophages treated with the Toll like receptor 2 agonist N-palmitoyl-S-[2,3-bis(palmitoyloxy)(2RS)-propyl]-[R]-cysteinyl-[S]-seryl-[S]-lysyl-[S]-lysyl-[S]-lysyl-[S]-lysyl-[S]-lysine x 3 HCl (Pam3CSK4). Cell viability and apoptotic cell death were compared morphologically and by in-situ tailing. With the help of the WST-1 test, cell viability was quantified, and by measurement of neuron-specific enolase in the culture supernatant neuronal damage in co-cultures was investigated. Intracellular calcium levels were measured by fluorescence analysis using fura-2 AM. Results: SH-SY5Y neuroblastoma cells transfected with the G93A mutant of SOD1 typical for familial ALS (G93A-SOD1) were more vulnerable to the neurotoxic action of pneumolysin and to the attack of monocytes stimulated by Pam3CSK4 than SHSY5Y cells transfected with wild-type human SOD1. The enhanced pneumolysin toxicity in G93A-SOD1 neuronal cells depended on the inability of these cells to cope with an increased calcium influx caused by pores formed by pneumolysin. This inability was caused by an impaired capacity of the mitochondria to remove cytoplasmic calcium. Treatment of G93A-SOD1 SHSY5Y neuroblastoma cells with the antioxidant N-acetylcysteine reduced the toxicity of pneumolysin. Conclusion: The particular vulnerability of G93A-SOD1 neuronal cells to hemolysins and inflammation may be partly responsible for the clinical deterioration of ALS patients during infections. These findings link infection and motor neuron disease and suggest early treatment of respiratory infections in ALS patients. [ABSTRACT FROM AUTHOR]